Chapter IVK6结构化学

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Chapt.4,Chapt,.4,1,Chapter IV Preparations and Reactions,of Coordination Compounds,1.,分类,(1),Werner complexes,The classification places all complexes that do not contain a,metal-carbon and all cyanide complexes in group 1,l,Normally have,saltlike,compounds,(2),Metal carbonyls and,organometallic,compounds,The group includes compounds that contain at least one,metalcarbon,bond.,l,Are usually covalent molecular materials.,2,2.,晶体的制备,(1),Group 1,l,Evaporate the solvent and cool the more concentrated,reaction mixture in an ice-salt bath.,l,Slowly add a solvent that is miscible with the solvent of the,reaction mixture but that does not dissolve the desired,compound.,l,If the desired complex is a,cation,it may be isolated by the,addition of an appropriate anion with which it forms an,insoluble salt.,3,(2),Group 2,l,Sometimes isolated by these same techniques of the,group 1,l,They can also be collected and purified by distillation,sublimation,and chromatographic processes.,4,4.1 Substitution Reactions in Aqueous Solution,1.,铜的配合物,Cu(H,2,O),4,2+,+4NH,3,Cu(NH,3,),4,2+,+4 H2O (1),blue dark blue,l,The dark-blue salt crystallizes from the reaction mixture,upon the addition of ethanol.,5,2.,铑及钴的配合物,K,3,RhCl,6,+3K,2,C,2,O,4,K,3,Rh(C,2,O,4,),3,+6KCl (2),Wine red yellow,Co(NH,3,),5,ClCl,2,+3en Co(en),3,Cl,3,+5 NH,3,(3),purple orange,These reactions are rather slow at room temperature,therefore,it is carried out on a steam bath.,6,3.The intermediate mixed,compexes,l,Some,successful syntheses of mixed compounds have been,achieved by limiting the concentration of a potential,ligand,.,K,2,PtCl,4,+en Pt(en)Cl,2,+2KCl (4),Red yellow,Pt(en)Cl,2,+2 NH,3,Pt(en)(NH,3,)Cl,2,(5),yellow colorless,7,4.2 Substitution Reactions in,Nonaqueous,Solvents,1.Reasons for using,nonaqueous,solvents,(1),the metal ion has a large affinity for water.,如,Al(III),Fe(III)and Cr(III),在水溶液中与碱性配体反应一般生成氢氧化物沉淀。,(2)the,ligand,is insoluble in water.,8,2.,实例,(1)Cr(III),配合物的合成,(the metal ion has a large affinity for,water),l,水合,Cr(III),在水溶液中与乙二胺反应生成氢氧化物沉淀,Cr(H,2,O),6,3+,+3en Cr(H,2,O),3,(OH),3,+3enH,+,(6),l,无水三氯化铬在乙醚中与乙二胺则可生成乙二胺的配合物,CrCl,3,+3en Cr(en),3,Cl,3,(7),在,DMF,中也可以高产率地得到乙二胺的配合物,Cr(DME),3,Cl,3,+2en cis-Cr(en),2,Cl,2,Cl (8),9,(2)Fe(II),配合物的合成,(the,ligand,is insoluble in water),l,Often it suffices to dissolve the,ligand,in a water-miscible solvent and then to add this solution to a concentrated water solution of the metal ion.,See p197,(9),Fe(H,2,O),6,2+,+3bipy Fe(bipy),3,2+,+6H,2,O (9),l,Metal complexes of,bipy,and,phen,are generally prepared in this way.,10,4.3 Substitution Reactions in the Absence of Solvents,l,The direct reaction between an anhydrous salt and a liquid,ligand,can be used to prepare metal complexes.,1.,氨作为配体时,A method applicable to the synthesis of metal ammines involves the addition of a metal salt to liquid ammonia followed by evaporation to dryness.,(1)Ni(II),配合物的合成,NiCl,2,+6NH,3,(liquid)Ni(NH,3,),6,Cl,2,(10),11,(2),铂配合物的合成,One method used for the preparation of Pt(en),2,Cl,2,or Pt(en),2,Cl,4,is the direct reaction between,ethylenediamine,and PtCl,2,or PtCl,4,respectively.,2.DMF,作为配体时,The methods to prepare some of these complexes were a direct reaction in the absence of any added solvent.,Co(ClO,4,),2,+6(CH,3,),2,SO Co(CH,3,),2,SO,6,(ClO,4,),2,(11),12,4.4 Thermal Dissociation of Solid Complexes,1.,释放出水,(1),铜的配合物,Cu(H,2,O),4,SO,4,H,2,O,Cu SO,4,+5 H,2,O (12),得到铜盐。,(2),铑的配合物,Rh(NH,3,),5,H,2,OI,3,Rh(NH,3,),5,II,2,+H,2,O (13),得到铑的碘氨配合物。,13,2.,释放出氨和胺,(1),铂的配合物,Pt(NH,3,),4,Cl,2,trans-Pt(NH,3,),2,Cl,2,+2 NH,3,(14),释放出氨，氯离子进入了内界,得到反式结 构。,(2),铬的配合物,Cr(en),3,(NCS),3,trans-Cr(en),3,(NCS),2,NCS (15),释放出乙二胺，硫氰酸根进入内界,得到反式 结构。,l,Cr(en),3,Cl,3,加热到,210,得到的是顺式产物,.,14,4.5 Oxidation-Reduction Reaction,l,For the hundreds of cobalt(III)complexes that have been prepared,the starting material was almost always some cobalt(II)salt.,1.Synthesis of Co(III)complexes with air oxidation,4Co(H,2,O),6,Cl,2,+4NH,4,Cl+20 NH,3,+O,2,4Co(NH,3,),6,Cl,3,+26 H,2,O (16),Co(H,2,O),6,Cl,2,+6 NH,3,Co(NH,3,),6,Cl,2,+6 H,2,O (17),4Co(NH,3,),6,Cl,2,+4NH,4,Cl +O,2,4Co(NH,3,),6,Cl,3,+4NH,3,+2 H,2,O (18),15,Question:Why cobalt(II)can been,oxidated,to cobalt(III),when they form coordination compound?,(1),Co(II,)d,7,Co(III,)d,6,(2),弱场配体，高自旋时,Co(II,)d,7,Co(III,)d,6,(3),强场配体，低自旋时,Co(II,)d,7,Co(III,)d,6,16,(4),强场配体，低自旋时,Co(II,)d,7,Co(III,)d,6,综上所述，水合钴离子二价的稳定，,中强场配体配合物中的钴离子三价的稳定,very easy,17,2.Synthesis of Co(III)complexes with other oxidizing agent.,For example:(1)O,2,and H,2,O,2,=H,2,O,(2)PbO,2,=Pb,2+,=PbCl,2,(3)SeO,2,=Se,18,3.Synthesis of Co(III)complexes with the particular oxidizing agent.,Co(EDTA),2-,+Fe(CN),6,3-,Co(EDTA)-+Fe(CN),6,4-,(19),pink violet,Co(EDTA),2-,+Br,2,(EDTA)CoBr,2,2-,pink rose,(EDTA)CoBr,2-,+Br (20),解释两个反应式的产物不同的内在 原因,4.,还原法,(1),镍的配合物,(,需要惰性无水的气体保护,),K,2,Ni(CN),4,+2K K,4,Ni(CN),4,(21),(2),铁的羰基配合物,(,对空气敏感，对水不敏感,),Fe(CO),5,+4KOH K,2,Fe(CO),4,+K,2,CO,3,+2H,2,O (22),19,4.6 Catalysis,1.,分类,(1)Heterogeneous catalysis,(2)Homogeneous